Use Showmiiwads or other similar program to extract the dump to raw files, then grab the /title/00010000 folder from it. I believe that's the correct folder for saves. To get these raw saves back onto your Wii, you'll need to use Savegame Manager GX. It should be able to get your saves on there. I forget how that program needs the save folder named, though, so you may want to play a game or two on your Wii, then dump the saves you make to see how it organizes them.